Fuel injection apparatus for injection engines



. 3 TSURUKICHI ONO 2,664,313

FUEL INJECTION APPARATUS FOR INJECTION ENGINES Filed July 28, 1950Patented Dec. 29, 1953 UNETED STATES PATENT @FFICE FUEL INJECTIONAPPARATUS FOR INJECTION ENGINES Tsurukichi Ono, Fukushima-Ken, JapanApplication July28, 1950, Serial No. 176,396

3 Claims. (Cl. 299-1075) lhis invention relates to improvements in fuelinjection apparatus for an injection engine, such as diesel engine, andmore particularly to the structural details of a needle valve therefor,the valve comprising two elements namely a valve body and its push rodwhich serves to keep said valve pressed against its seat correctly.

It is a particular object of the invention to provide a fuel injectionassembly wherein the needle valve has a regular contact with its valveseat during operation. It is a further object of the invention toprovide a fuel injection apparatus for a diesel engine, wherein the fuelis atomized completely thus increasing materially the efiiciency of theengine. It is still a further object of the invention to provide a fuelinjection apparatus for an injection engine, which is of sturdyconstruction and which will last much longer than conventional fuelinjection apparatus.

The present invention offers a solution of the partial defacementproblems of the needle valve and the valve seat. In accordance with thepresent invention no side pressure occurs between the sliding member andits guide member, namely, the needle valve spindle and its guide, and asthe result, the partial defacements of the needle valve and its seatwhich above mentioned, are positively prevented.

The novel features which we believe to be characteristic of thisinvention are set forth with particularity in the appended claims. Thisinvention itself both as to its construction and function may beunderstood by reference to the following description taken in connectionwith the accompanying drawing in which:

Figure 1 is a longitudinal sectional view of a constructional form offuel injection apparatus embodying this invention.

Figure 2 is a transversal sectional view taken on the line A-A of Fig.1.

Figure 3 is a longitudinal sectional view of another modification ofthis invention.

Referring to Figs. 1 and 2, l is the valve housing having a longitudinalbore 2 and a valve spindle 3 is slidably mounted within the bore. Thespindle 3 terminates in a needle valve head 4 which cooperates with aseat 5 provided in the valve housing. At the bottom of the housing I, afuel chamber ti communicates with the bore 2 at the lower end of thebore. Fuel injection apertures or holes I lead from the space below theseat 5 to a point externally of the housing I. The fuel may be suppliedto the chamber 6 through conduits 8 by the use of any suitable type offuel pump (not illustrated).

' Along its central axis, the spindle 3 is formed with a longitudinalbore 9 which. terminates at its lower end in a concave surface wand theangle of the surface is preferably about 120 degrees. The upper end ofthe bore is provided with a screw-threaded section l l, by means ofwhich the valve spindle may be removed from the bore 2, when desired.Any convenient type of threaded bar may be employed to engage thethreaded section H.

In the bore of valve spindle 3 a push rod I2 is inserted loosely, andthe push rod l2 has a conical lower end it supported on the bottom ofsaid bore 9 by its conical end. The end I3 of the push rod engages thesurface it in the bore 9 and the angle of the end i3 is approximatelydegrees.

Therefore, it will be seen that the axis of the push rod coincidesexactly with the axis of needle valve and the contacting points of themembers will be on said coincided axis. The push rod I2 is provided withan area id of enlarged diameter near the upper end and the periphery ofthe area it slidably engages the wall of the bore 2 at a point above thespindle 3. At its upper end the push rod is pressed downwardly by aspring as is customary in the art. The spring, through the push rodserves to maintain the valve 4 against the seat 5. The pressure of thespring is less than that of the fuel which is forced into the chamberthrough the conduits 8.

So when the fuel pump is in action and the compressed fuel has beenforced into the fuel chamber through the conduits 8, the needle valvewill be lifted from the valve seat upwardly against said spring action,and then the fuel will be injected out from the injection holes I in anatomized state. When the fuel pump has stopped, however, the springaction overcomes the pressure of fuel chamber, so the push rod thruststhe valve spindle through its end 13 resting on the surface ll] of thebore of the spindle thereby urging the valve against its seat.

In accordance with the present invention, the needle valve is pressed onthe valve seat only by the conical end it of push rod which contactswith said valve at its concaved conical surface Ill, and as theircontact point is on the coincided axis of these two members, the needlevalve will fit in its seat exactly.

In conventional apparatus, a single valve spindle is used and itterminates in a valve head and spring means cooperates with the upperend of the spindle to maintain the head against its seat. Thus, acertain amount of side pressure acts upon the spindle when the valvehead is moved toward its seat and this pressure is due to the clearanceexisting between the spindle surface and the inside surface of the bore.This side pressure causes wearing of the spindle, the needle valve andparticularly the valve seat.

It is a matter of common knowledge that the partial defacements of thevalve and valve seat causes many undesirable phenomena-for the in?jection device, such as supplying unatomizedfuel' to engine, difficultyof repairs and lack of durability etc.

With the present invention, these side. pres. sures do not occur sincethe spring pressure thrusts only the push rod and the end of the rodpresses the valve spindle and as previously men--- tioned, the contactpoint betwcenthe=rodandthel spindle is on the same central axis of themembers.

Therefore, even though the push rod has inclined and diverted from theaxis of-valve spin die by the spring pressure, no sidepressure takesplace betweenthe valve spindle audits bore or taotingsurfaces which-holdthe steel ball 15: are,

both of concave configuration and their angles are about 120.

Theinvention is not limited to the constructional form here shown anddescribed which is, as above stated, given only by way'of example,

as the invention may be performed in. other ways, without departing fromits principle. I claim:

1. In a fuel injection. assemblagefor internal combustion engines, avalve body having a fuel.

chamber therein, means defining .a fuel feed .con-

duit in the body leading froma supply source.

to the fuel chamber, fueldischargerports in the body below said chamberandin communication therewith, further means defining an-invertedfIZLIStOr-COYHCBJ valve seatinthe body. intermediatethefuel chamber andthe, dischargeports a bore extending longitudinally of the body from oneend of the body and merging with the fuel chamber, a valve spindlelodged in and reciprocable in said bore, a conical head on said spindleadapted to cooperate with the wall of the valve seat to open and closecommunication between the fuel chamber and the discharge ports, the saidvalve spindle being provided with a bore extending longitudinallyfromithe end "remote from the conical head and terminating in a seat, apush rod slidably mounted within the spindle bore with the axis of thepush rod coinciding with the axis. of the valve spindle, a sphericalobjectllodged between the inner end of the push rod and the seat in saidspindle defining a contact: area". between, the push rod and the valvespindle, falling, on the axis of the push rod and the spindle, anenlarged area on the said push rod at. a point above the valve spindleof the same diameter as the outer diameter of the valve spindle slidablyengagingthewall of the bore in said body to guide, the push rod. withinthe spindle bore,,and means, operatively asso ciated with said push. rodto maintain, the conical head, of the, valve, spindle, normally in, engagement with thefrusto-oonical seat.

2; A fuel injection assemblage as, defined in and claimedby claimlfurther characterizedin that. saidspherical' obj ect'. is, a steel ball.

3..A fuel injection assemblage as dfil1ed in and claimed by claim '1further characterized in that said push rod is provided with a concavedepression in the end thereof and the valve spindleis provided with aconcave'seat, the spherical object being lodged between said depressionand concave seat.

TSURUKICHI ONO.

References Cited in the file of this patent UNITED STATES PATENTS.

Numb er Name: Date.

1,152,733 Hauser Sept; 7, 1915. 1,761,122 Groif June 3,, 19.36 2,020,666Veglio Nov..12, 193.5 2,101,682 Klafstad Dec; 7,.1937 2,108,647 BroezeFeb. 15,1938 2,261,461 Falls; Nov. 4,1941

FOREGN PATENTS.

Number. Country Date 491,821 Germany: Feb. 12; 1930'

